[Formulajones]

Originally Posted by zippy

So, my 455HO (470cid) runs great, get about 15mpg when drive easy. But when hard accel, say from 30mph, Pull out pass someone, WOT itll starve for fuel after a second. Then kinda come back, If I ease off a little, she fine.
Also, If I slowly ease into her, she fine all way up to top speed, 6000RPM for long Hwy run. AKA, dusting that BMW who thought he was fast on the 2 mile straight.

I have Elec fuel pump, Holley Blue, and a .110" inlet seat.
Would you think its the small inlet seat not letting enough in when I really accel hard? Letting bowl drop and fuel slosh to uncover jets? Ir pump not keeping up to the acceleration demands?

Only happens on a Hard launch or accel when there lots of 'push you into the seat' G forces.
I can burnout for days no issues either

Kinda sounds like you don't have enough fuel in the tank and aggressive driving sloshing the fuel is uncovering the pickup for a second.

[Dick Boneske]

If this was a fuel delivery problem, float set too low, or too small fuel line, the problem would show up doing burnouts and early into wide open throttle.

The most likely source of the problem is the secondary air valve opening too early. simply tighten the spring about 1/4 turn and try it.